Trimmer mechanism for sewing machines



Jan. 23, 1934. F. M. CARD TRIMMER MECHANISM FOR SEWING MACHINES Filed Dec. .1, 1932 2 Sheets-Sheet gwue/Mm fiederic card wwweaw WWW Jan. 23, 1934. CARD 1,944,543

TRIMMER MECHANISM FOR SEWING MACHINES Filed D60. 1, 1952 2 Sheets-Sheet 2 flatly/MM;

Patented Jan. 23, 1934 UNITED STATES PATENT OFFICE TRIMMER MECHANISM. FOR SEWING MACHINES Application December 1,1932. Serial No. 645,201

11 Claims.

This invention relates to improvements in trimming mechanisms for sewing machines and has for its primary object to provide for more ready manipulation of the work in the operation of trimming one or more work-plies. A more specific object of the invention is to improve the underedge trimming mechanism of the U. S. Patent to J. F. Hcerig, No. 1,852,611, April 5, 1932, and to provide a so-called Barber trimmer mechanism of the work-overhanging type,

according to which the trimming knife is positively actuated and may be conveniently rendered inoperative.

The invention consists in the devices, combinations and arrangements of parts hereinafter described in connection with the accompanying drawings which illustrate a preferred embodiment of the improved trimming mechanism and in which:

Fig. 1 is a view in front elevation and partly in vertical section of a portion of a sewing machine having the improved trimming mechanism, and showing the trimmer-knife in its operative position. Fig. 2 is a rear side elevation, partly in section, of a portion of the trimmer-bracket, with the knife-carrier swung into its inoperative position. Fig. 3 is a top-plan view of the trimmeractuating mechanism, with the trimmer-bracket partly broken away. Fig. 4 is a top-plan view of the knife-carrier and its actuator. Fig. 5 is a bottom plan View of the knife actuator, with the'knife-carrier swung into inoperative position. Fig. 6 is a top-plan view of the throatplate and feed-dog, and showing a section of the trimmer-knife fin.

Referring to the drawings, the sewing machine has a frame which preferably includes an upstanding work-supporting post 1 upon the upper end of which is suitably secured a throat-plate 2. overhanging the post 1 is a bracket-arm 3 in which is rotatably journaled a horizontally disposed main actuating shaft 4 carrying at one end a crank-disk 5. The crank-disk 5 is operatively connected by means of a crank-pin 6 and a link 7 to a pin 8 extending from a collar 9 clamped upon a needle-bar 10, carrying at itslower end a needle 11 and journaled for vertical reciprocation in suitable bearings provided in the head of the bracket-arm 3. The needle 11 cooperates with a suitable loop-taker (not shown) within the worksupporting post 1 and the work is advanced past the needle by a feed-dog 66 carried by mechanism also disposed within said post 1. Opposed to the feed-dog is a presser-roller 12 rotatably journaled in an arm 13 of a presser-bracket 14 suitably secured upon the lower end of a springedepressed presser-bar 15,. A

At the under side of the bracket-arm 3 is a boss 16 which is flattened on its under face to re-.- ceive the flanged base 17 of a trimmer-bracket 69 18 detachably secured to said boss by screws 19. The trimmer-bracket 18 is elbowed, whereby its free end extends under the bracket-arm 3 toward the head end of the latter, said bracket 18 terminating at its free end in a tubular split boss .5,. 20 providing a vertical bearing aperture 21. Disposed in the bearing aperture 21 of said boss 20, and clamped rigidly therein by screws 22, is a bearing bushing 23 in which is journaled a vertically disposed rock-shaft 24 extending beyond the opposite ends of said boss 20 and its bushing 23. The longitudinal axis of the rock-shaft 24 lies preferably in a vertical plane containing the longitudinal axis of the main shaft 4.

Clamped by a screw 25 upon the upper end :of 5- the rock-shaft 24 is the split hub of a horizontally disposed crank-arm 26 directed toward the elbow of the bracket 18 and having at its free end a ball-joint connection with one end of an extensible 11m; 27. The other end of the link 27 9. has a ball-joint connection with the lower .end of a depending rock-arm 28 having its split 'hub clamped by a screw 29 upon a rock-shaft 30. The rock-shaft 30 is disposed substantially par.- allel to the actuating shaft 4 and is journaled in bearing lugs, as 31, at the rear side of the bracket-arm 3. Secured upon the rock-shaft 30 is an actuating arm 32 having a fork 33 embracing an eccentric 34 upon the actuating shaft 4, said arm 32 extending through a suitable opening 35 provided in the rear side of the bracket-arm 3. Fastened by a screw 36 upon the lower end of the vertical rock-shaft 24 is a boss 37 inter.-. mediate the endsof a horizontally disposed knifeactuating lever 38 extending transversely of the line of seam formation, said boss 37 having a circular periphery preferably concentric with the rock-shaft 24. 2 Auxiliary. to said lever 33 is a supporting member 39 secured by screws 40 in a recessed guideway in the under face of the lever 38 for adjustment lengthwise of said lever, i. e., for adjustment toward and from the line of seam formation. Threaded into said support"- ing member 39 from the under side thereof is a screw 41 fastening a flanged pivot-bushing .42 to the under face of said member 39. Preferably, the pivot-bushing 42 is located axially in vertical alinement with the axis of the rockshaft 24, said bushing pivotally supporting a horizontally disposed knife-carrier 43 having a 9 downwardly inclined knife carrying end portion 44. Secured by screws 45 upon said inclined end 44 of the knife-carrier for adjustment lengthwise of said inclined end 44 is the longitudinally slotted shank 46 of a trimmer-knife bent to extend substantially horizontally from the knife-carrier and to provide a fabric-ply separating blade 47. The separating blade 47 is spaced from the upper end of the work-support and terminates in a vertically depending fin 48 having a sharpened cutting edge 49 opposed to the direction or" feed of the work. The knife-fin 48 has a horizontal arcuate path of movement adjacent to the path of reciprocation of the needle 11 and is in sliding engagement with the usual curved shoulder provided upon the throat-plate, whereby a work ply supported upon the throat-plate is trimmed as it advances past the needle.

An upper ply of work is guided away from the knife-fin 48 by the separating blade 47 of the knife, the edge of said upper work-ply being guided past the needle by a segmental edgeguide 51 resting upon the separating blade 47 of the knife and having a slotted shank 52 overlying the knife-shank 46 to be secured in adjusted position by one of the screws 45.

The end of the knife-carrier 43 opposite to the knife end thereof is reduced in thickness to thereby provide a flexible tail 53 yieldingly entering a notch 54 in the depending end or flange 55 of an adjustable coupling arm 56 comple mental to the actuating lever 38. The coupling arm 56 overlies the actuating lever 38 and is apertured to pivotally embrace the boss 37 of said lever 38, whereby the arm 56 may be adjusted horizontally about the vertical axis of the rock-shaft 24. The coupling arm 56 is secured upon the actuating lever 38, for vibration there- -with, by a screw 5'7 passing through an arcuate 40 slot 58 in the arm 56 and having the axis of the rock-shaft 24 as its center of curvature. By adjustment of the arm 56, the cutting edge 49 of the knife-fin 48 may be advanced to compensate for the shortening of the fin 48 occa- 'sioned by regrinding of its cutting edge.

In the operation of the machine, the vertical rock-shaft 24 imparts unison horizontal vibratory movements to the actuating lever 38 and 1 coupling arm 56 whereby, in the operative position of the trimmer-knife, the carrier 43 vibrates in unison with said lever 38 to actuate the trimmer-knife. Trimmer-knives of the present character are commonly employed in undertrimming thelinings of shoe-uppers and similar work and as the actuating mechanism is entirely supported by the overhanging bracket-arm of the machine, there is no obstruction to the free turning of the work upon its supporting post.

' To discontinue trimming the work, the operator manually depresses the flexible tail 53 of the knife-carrier 43 to disconnect it from the notch 54 of the coupling arm 56, whereupon said carrier is free to be swung about the pivot-bushing 42 to carry the knife away from its operative position. Preferably, the knife is swung rearwardly into an inoperative position determined by a latch-pin 59 which is located at the rear side of the bracket-boss 20 to yieldingly enter a recess 60 in the upper face of the trimmer-knife carrier. The latch-pin 59 is slidingly supported for vertical movement in a guide-aperture 61 provided in an auxiliary bracket 62 secured by screws 63 upon the rear face of the primary bracket 18. A coil-spring 64 embraces a reduced portion of the latch-pin within the bracket-aperture 61 to urge the latch-pin downwardly, a stop-nut 65 adjustably limiting downward movement of said latch-pin under the action of the spring 64.

Having thus set forth the nature of the invention, what I claim herein is:-

1. In a sewing machine, a work-support, a

bracket-arm overhanging the work-support, a vertically reciprocatory needle, work-feeding mechanism, a horizontally vibratory trimmerknife carrier supported by said bracket-arm to overhang the work-support, a horizontally vibratory actuating lever operatively connected with said trimmer-knife carrier, a trimmer-knife secured upon said carrierv and having a vertically depending fin provided with a cutting edge opposed to the direction of feed of the work, and means for vibrating said actuating lever. 2. In a sewing machine, a work-support, a bracket-arm overhanging the work-support, a vertically reciprocatory needle, work-feeding mechanism, a horizontally vibratory trimmerknife carrier supported upon said bracket-arm to overhang the work-support, an actuating lever, releasable coupling means connecting said trimmer-knife carrier for movement with said lever, and a trimmer-knife secured upon said carrier and having a vertically depending fin provided with a cutting edge opposed to the direction of feed of the work.

3. In a sewing machine, a Work-support, a bracket-arm overhanging the work-support, a vertically reciprocatory needle, a horizontally vibratory actuating lever journaled upon said bracket-arm above the work-support, a trimmerknife carrier, means operatively connecting said lever with said carrier including a coupling arm adjustable about the fulcrum-axis of said actuatin lever, means for vibrating said actuating lever, and a trimmer-knife secured upon said carrier.

4.1m a sewing machine, a work-support, a bracket-arm overhanging the work-support, a vertically reciprocatory needle, a horizontally vibratory actuating lever journaled upon said bracket-arm above the work-support, a trimmerknife carrier, a pivotal support for said trimmerknife carrier upon said actuating lever, a coupling arm supported for horizontal adjustment about the fulcrum-axis of said actuating lever and releasably connected with said trimmerknife carrier, means forvibrating said actuating lever, and a trimmer-knife, secured upon said carrier.

5. In a sewing machine, a work-support, a

support, an actuating lever carried by said rock shaft above the work-support and operatively connected with said trimmerknife carrier, a trimmer-knife secured upon said carrier and having a depending fin provided with a cutting edge, and means for oscillating said rock-shaft from said rotary actuating shaft.

6. In a sewing machine, a work-support, a bracket-arm overhanging the work-support, a vertically reciprocatory needle, work-feeding mechanism, and a trimmer mechanism comprising a vertically disposed rock-shaft, a bearing for said rock-shaft upon said bracket-arm, a horizontally vibratory actuating lever carried by said rock-shaft, a trimmer-knife carrier pivotally supported by said lever for horizontal swinging movements relatively to said lever, releasable coupling means connecting said trimmer-knife carrier for movement with said lever, a trimmerknife secured upon said carrier and having a depending fin provided with a cutting edge opposed to the direction of feed of the work, and means for actuating said rock-shaft.

7. In a sewing machine, a work-support, a bracket-arm overhanging the work-support, a rotary actuating shaft journaled in said bracketarm, a vertically disposed rock-shaft journaled upon said bracket-arm, an actuating lever carried by said rock-shaft for horizontally vibratory movements above the work-support, a trimmerknife carrier supported by said actuating lever for movement relatively thereto, releasable coupling means connecting said trimmer-knife carrier for movement with said actuating lever, a trimmer-knife secured upon said carrier and having a horizontally disposed work-ply separating blade provided with a depending fin having a cutting edge, and means for oscillating said rockshaft from said rotary actuating shaft.

8. In a sewing machine, a work-support, a bracket-arm overhanging the work-support, a vertically disposed rock-shaft journaled upon said bracket-arm, an actuating lever carried by 'said rock-shaft above the work-support, a supporting member adjustably secured upon said lever, a trimmer-knife carrier pivotally sustained by said supporting member, coupling means releasably connecting said trimmer-knife carrier for movement with said lever, and means for oscillating said rock-shaft.

9. In a sewing machine, a work-support, a bracket-arm overhanging the work-support, a vertically disposed rock-shaft journaled upon said bracket-arm, a lever extending substantially horizontally from said rock-shaft above the worksupport, a trimmer-knife carrier pivotally mounted upon said lever for horizontal swinging movements relative to said lever, releasable coupling means operatively connecting said trimmer-knife carrier to said lever, latching means for releasably holding said trimmer-knife carrier in an inoperative position, and means for oscillating said rock-shaft.

10. In a sewing machine, a work-support, a bracket-arm overhanging the work-support, a vertically disposed rock-shaft journaled upon said bracket-arm, means for oscillating said rockshaft, a lever extending substantially horizontally from said rock-shaft above the work-support, a trimmer-knife carrier pivotally mounted upon said lever for horizontal swinging movements relative to said lever, a, coupling arm operatively connecting said trimmer-knife carrier to said lever, and means for securing said coupling arm to said lever for adjustment about the axis of oscil lation of said rock-shaft.

11. In a sewing machine, a work-support, a bracket-arm overhanging the work-support, a rotary actuating shaft journaled in said bracketarm, a trimmer-bracket disposed at the under side of said bracket-arm above the work-support, a vertically disposed rock-shaft journaled in said trimmer-bracket, means for oscillating said rockshaft from said rotary actuating shaft, a lever extending substantially horizontally from said rockshaft above the work-support, a trimmer-knife carrier supported for movement into and out of operative position relatively to said lever, releasable coupling means connecting said trimmer-knife carrier to said lever for movement therewith, and latching means carried by said trimmer-bracket for releasably holding said trimmer-knife carrier in an inoperative position.

FREDERIC M. CARD. 

